Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Bio Senior Year U1
| Question | Answer |
|---|---|
| Adaptations for Gas Exchange/Vapor Exchange | Thin/Flat Leaves, Waxy Cuticle (upper epidermis), stomata (lower epidermis), spongy mesophyll, veins (vascular bundles) |
| Leaves adaptation | Large, thin surface area that allows diffusion of gases. Also allows them to absorb sunlight |
| Waxy Cuticle Adaptation | Hydrophobic - water cannot escape easily - It's also a layer of moisture that allows gases to diffuse easier |
| Stomata Adaptation | Small pores that help gas enter and exit the plant. They are mostly on the bottom of the plant to prevent water loss and it also protects them. They are regulated by guard cells to open and close |
| Spongy Mesophyll Adaptation | They have irregular shape that allows gas to move through/across them. Contains air spaces that allow gas to travel through them. |
| Veins (Vascular Tissue) Adaptation | Helps transport water/nutrients. Water diffuses out of the leaf through the veins via transpiration |
| Transpiration | Loss of water vapor through leaves, stems, other above ground parts of the plant. Vapor diffuses out through the stomata. This also helps with regulating the temperature of the plant |
| How does transpiration happen? | Via Negative pressure. It pulls on water molecules because of waters cohesive and adhesive properties which results in capillary action. |
| Tool to measure rate of transpiration? | Potometer |
| How would you measure rate of transpiration? | Cut plant stems under water and place them in the potometer in an air tight seal. On the other side of the potometer there are graduations. As the plants transpires, it will take up water from the surroudings to replace the lost water. |
| Factors affecting transpiration | Temperature, humidity, wind, light intensity |
| Temperature affect on transpiration | At higher temperatures, molecules move faster out of the stomata. The air outside of the plant can also hold onto more water molcules. This increases transpiration |
| Humidity affect on transpiration | At higher humidities, there is a higher concentration of water vapor outside of the plant. This lowers the concentration gradient of water from inside to outside the plant. This decreases transpiration |
| Wind affect on transpiration | In windier conditions, the water vapor is moved away from the plant faster thus increasing the concentration gradient. This increases transpiration |
| Light intensity affect on transpiration | Guard cells open wider under more light intensity to allow carbon dioxide to diffuse into the leaf for photosynthesis. This increases the area the water vapor can diffuse out from. This increases transpiration. |
| Stomatal density | Basically - get AREA of the fov (so radius * radius*pi) and then put either number of stomata or mean stomata over that and BOOM - stomatal density (units are stomata/mm^2) |
| Epidermis Adaptation | Typically only one cell thick and transparent. Allows sunlight to hit cells for photosynthesis |
| Xylem (what it transports) | water/dissolved minerals ONLY UP the plant |
| Phloem (what it transports) | Sucrose/Amino Acids up AND down the plant |
| Xylem adaptations | Formed with specialized (dead) cells, walls strengthened with Lignin, pits, |
| Dead xylem cells | dead cells mean that the xylem are hollow tubes that are specialized for the transport of water |
| Lignin | Complex polymer that binds to cellulose and strengthens/increases the regidity of the xylem. Waterproofs the xylem which makes it impermeable to water. |
| Pits | Regions where cell wall is thinner/contains no lignin. Allows for the lateral movement of water in/out the xylem |
| Why water enters roots | due to high mineral ion solute concentration in root cells |
| When does root pressure occur | When transpiration is insufficient |
| Root pressure | Positive water pressure potential. Minerals ions are actively transported from soil to Caspian Strip. This causes water to move to an area with lower water potential (Xylem) |
| Water pathways Root to xylem | Symplastic and Apoplastic pathways |
| Symplastic pathway | Water moves from root to xylem via cytoplasm of adjacent cells (through plasmodesmata) |
| Apoplastic pathway | Water moves through the cell wall of cells via capillary action |
| How do the pathways converage? | The apoplastic pathway converges with the symplastic pathway before hitting the Caspian strip |
| Translocation | The movement of nutrients (Sucrose and Amino Acids) up and down the phloem from sinks to sources |
| Vein used in translocation | Phloem |
| Source | area of the plant that produces/has stored nutrients |
| Sink | area of the plant that uses/stores nutrients |
| Example of source | Leave |
| Example of sink | Growing Tissue |
| Process of translocation | Sugars ACTIVELY pumped to phloem from source. Solute concentration is increased. Water from xylem moves in via osmosis. This creates pressure and moves nutrients to where it needs to go. Once they get to the sink, solutes are unloaded and water back xylem |
| Sieve tube elements | arrange themselves end to end to for sieve tubes |
| Sieve tubes | long tubes that form phloem |
| Sieve plates | connect sieve tube elements |
| Sieve tube element cells | Contain limited cytoplasm, few mitochondria. Missing many organelles such as nucleus. This is in order to maintain transport efficiency |
| Companion cells | support sieve tube elements. They have many mitochondria and transport proteins for active transport. Have plasmodesmata to connect to sieve tube elements |
Created by:
English1002